Design and Control Method of LCL Filter in High Performance Photovoltaic Inverter
Compared with traditional L-type and LC type filters,the LCL type filter of photovoltaic inverters has better suppression ability for high-order harmonics injected into the grid under the same inductance,and the harmonic attenuation is very obvious.However,using LCL type filters can easily generate resonance peaks,affecting the stability of the entire system.In view of this,this paper proposes a design scheme for a photovoltaic grid connected inverter based on LCL filters.The scheme analyzes the direct torque control strategy of the photovoltaic grid connected inverter.Simulation tests show that the inverter effectively suppresses the resonance problem of LCL filters and improves the control ability of photovoltaic grid connected voltage and current.This design is divided into five parts:main circuit,LCL filter,control system,three-phase phase-locked loop,and simulation.The simulation results show that the total harmonic distortion rate(THD)of the grid connected current is 3.06％,which meets the industry standard of THD＜5％.The peak grid connected current is 107.4 A,which can meet the preset requirements.The results indicate that the proposed method effectively suppresses the resonance problem of LCL filters and improves the control capability of photovoltaic grid connected voltage and current.
万方数据
维普
